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Project title

Modelling the role of clouds in forming PM2.5 aerosol

Primary Funding Agency

Environmental Protection Agency

Co-Funding Organisation(s)

n/a

Lead Organisation

National University of Ireland Galway (NUIG)

Lead Applicant

Colin O'Dowd

Project Abstract

This thesis presents the results of measurements and modelling of marine aerosols.Eddy correlation measurements of aerosol fluxes for sizes between 10 nm and 1000nm show a strong correlation with wind speed. Micrometeorological parameters andfootprint model calculations have shown that the 22m tower is a suitable location tomeasure fluxes which are representative of the open ocean. These measurementsrepresent the first pseudo-size-segregated aerosol flux measurements indicating asignificant contribution in the Aitken mode (50% of the sub-micron fluxes). Fluxes of thismagnitude can readily contribute significantly to background marine aerosolconcentrations and should be considered as important as secondary formation ratesover the oceans. Fluxes of new secondary aerosol particles during nucleation events inthe coastal environment are reported for the first time. Events are divided into twotypes based on the prevailing wind direction. During tidal related nucleation eventsnew particle fluxes are typically of the order of 109-1010 particles m-2s-1 with bothupward and downward fluxes being of similar magnitude. A strong correlation (r2=0.86)was found between total particle number concentration and total (positive) number fluxwhen air masses were not affected by multiple sources suggesting that continuousmeasurements of particle number concentration at Mace Head can be converted into asource flux.

Grant Approved

�73,909.00

Research Hub

Climate Change

Research Theme

Trans-Boundary Air Pollution/Short Life Climate Forcers

Start Date

01/10/2002

Initial Projected Completion Date

n/a